The coupler assemblies on railcars sometimes do not operate properly in lock set. When the coupler is in the lock set position, the couplers are still engaged, but pulling forces between the railcars allows them to be pulled apart. The knuckle of the coupler may jam against the lock, preventing proper knuckle rotation. In some cases, may be as much as 50% of the time, knuckle and lock interference occurs in lock set, requiring the user to lift and hold the uncoupling lever in its most raised position to facilitate uncoupling. The traditional focus when addressing lock set jamming concerns between the knuckle and lock was on the lock and its interface with the thrower.
The options for addressing these problems are limited if the focus is only on the locations addressed in previous patents, such as U.S. Pat. Nos. 2,350,470; 2,709,007; 3,850,312; 4,084,705 and 4,363,414, all of which are herein incorporated by reference in their entirety. The options are also limiting when the focus is only on the mating parts of the system.
Other complications when attempting to solve this problem include the inability to completely measure (scan) to a very accurate level (+/−0.001″) all the surfaces of each component (either theoretically or from actual production parts), create a very accurate CAD model (+/−0.001″) of each part, and then create a working assembly of the system. Furthermore, the designer may not have the ability to use that model to investigate the issues, and to model and then simulate the proposed design changes to the model. In the past, the companies with the design engineering talents were either not interested in, or unable to undertake the time, provide the necessary engineering resources and/or spend the money necessary to investigate the concerns to the detail necessary to identify the concern, and then design a fix to these concerns. Modern day computer software and hardware is now available (at an attainable cost) and provide the tools necessary so that those that are experts in the field can use these tools to solve the problems that were here-to-for unsolvable.
There is a need to improve knuckle rotation to eliminate such jamming without delineating significantly from the accepted coupler assembly.